My blazer originally had body molding so the holes were already there. I used a combination of the original type clips and some 3m molding double sided tape to secure it to the truck. The molding is all the same as a shortbox except for the piece in front of the rear tire. I pieced all of it together from any place i could find a deal like ebay and lots of google searching it was all new reproduction suff. total price for all the molding was around $200 - $240 if i remember right.
I looked through some of my stuff some of the molding came from this site
www.chevroletrestorationworld.com